The Fundamental Unit of Life — Science STD 9 — Question

The phenomenon of change of a liquid into the gaseous state at any temperature below its boiling point is called:

When will a body under the action of several forces have 0 acceleration? 

Which of the following is not a mixture?

1. Kerosene.
2. Air.
3. Alcohol.
4. Petrol.

The upward force acting on the body immersed in a fluid is called:

The rate of doing work is called .....:

The ratio of moles of atoms in 12g of magnesium and 16g of sulphur will be:

1. 3 : 4
2. 4 : 3
3. 1 : 1
4. 1 : 2

The speeds of sound in four different media are given below. Which of the following is the most likely speed in m/s with which the two under water whales in a sea talk to each other when separated by a large distance?

1. 340
2. 5170
3. 1280
4. 1530

Crossing between genetically dissimilar plants to obtain crops having useful characteristics:

Which of the following vibrates when a musical note is produced by the cymbals in an orchestra?

1. Stretched strings.
2. Stretched membranes.
3. Metal plates.
4. Air columns.